Ribbon breaking for high speed surface driven winders

ABSTRACT

A process for winding yarn into a cylindrical-bodied substantially flat-ended package by traverse winding layers of helical coils of yarn on a surface-driven package is improved by not only breaking ribbon formation by the known waveform (minor modulation of inverter output to the traverse motor) from a preset point, but also modulating the set point to create a major modulation having a minor modulation superimposed along or within the modulated set point waveform.

United States Patent [1 1 Peckinpaugh Mar. 26, 1974 [5 RIBBON BREAKING FOR HIGH SPEED 3,402,898 9/1968 Mattingly .v 242/181 x SURFACE DRIVEN WINDERS 3,638,872 2/1972 Jennings 242/l8.l

[75] Inventor: Frank Lee Peckinpaugh, Colonial Heights, Va.

[73] Assignee: Allied Chemical Corporation, New

York, NY.

[22] Filed: Apr. 18, 1972 [21] Appl. No.: 245,062

[52] US. Cl. 242/18.1, 242/43 [51] Int. Cl B65h 54/38 [58] Field of Search 242/18.1, 43

[56] References Cited UNITED STATES PATENTS 2,763,824 9/1956 Bacheler 242/l8.l X 3,241,779 3/1966 Bray et al. 242/l8.l

Primary Examiner-Stanley N. Gilreath Attorney, Agent, or FirmRichard A. Anderson [57] ABSTRACT A process for winding yarn into a cylindrical-bodied substantially flat-ended package by traverse winding layers of helical coils of yarn on a surface-driven package is improved by not only breaking ribbon formation by the known waveform (minor modulation of inverter output to the traverse motor) from a pre-set point, but also modulating the set point to create a major modulation having a minor modulation superimposed along or within the modulated set point waveform.

3 Claims, 9 Drawing Figures PAIENTEBmzs 1914 saw 2 or 5 FIG. 2

FIG. 3

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FQOIDQ'ION (HSVH d0 AONHI'JOHEH BASE l2 l3 I4 I 2 3 4 5 6 7 8 9 l0 RUNNING TIME (MINUTES) m ru) :0 'qn N IVAHHLNI ONOOBS 0%. 83d CEINUOA SNOBBIU d0 HBBINON FIG. 6

RIBBON BREAKING FOR HIGH SPEED SURFACE DRIVEN WINDERS BACKGROUND OF THE INVENTION This invention relates to crosswinding of yarn, particularly to improved ribbon breaking for high speed surface driven winders.

The present technology of surface driven winders for synthetic fibers employs an inverter with a minor modulation of the electrical output frequency and voltage to drive the traverse motor and obtain ribbon breaking by varying the speed of the traverse cam with respect to the yarn delivery speed. This method modulates the inverter output frequency by a fixed percentage about a pre-set point with a definite period of oscillation.

However, due to winding geometry, this prior art minor modulation of inverter output along a pre-set straight line creates multiple ribbons at various time periods during winding. By ribbon is meant yarn laid down substantially on top of or along the same path as the previously wound yarn. This repeated duplication of yarn path on the package creates a ridge or ribbon on the package, causing an out-of-round package, bouncing winder chucks, causing heavy traverse motor loads, and yarn damage. Successful ribbon breaking also must not interfere with forming a good flat-ended cylindrical package without flaws such as bulge, high shoulders, overthrown ends (stitches), eyebrows and other defects disclosed in U. S. Pat. No. 3,638,872 to Jennings. Pertinent portions of U. S. Pat. No. 3,638,872 to Jennings are hereby incorporated by reference. Note that Jennings requires simultaneous modulated drive roll speed.

Another method of ribbon breaking is taught in U. S. Pat. No. 3,241,779 to Bray et al., hereby incorporated by reference. Bray et a]. have overcome the ribbon formation at wind ratios (traversal ratios) of whole numbers and certain fractions thereof by providing a pre-set initial traverse rate then decreasing it, having a continued short term variation superimposed on the initial pre-set rate and along the decreasing rate.

SUMMARY OF THE INVENTION This invention improves ribbon breaking by modulating traverse rate in both a minor and major modulation. The prior art minor modulation is a waveform superimposed along a straight line pre-set point. Pre-set point is defined by the point shown in FIG. 5. By straightline pre-set point is meant the imaginary straight line described by tracing the pre-set point shown on FIG. parallel to the base line of the graph, as for example, Section C in FIG. 3 of U.S. Pat. No. 3,638,872. This invention significantly reduces ribbons by modulation of the set point away from a straight line to cause the major modulation. This waveform is a plot of frequency versus time for the electric input to the traverse motor. Examples of this minor modulation along a major modulated curve are shown in FIGS. 4 and 7. The FIG. 4 major modulated waveform is sinusoidal, while FIG. 7 is saw-tooth configuration in the major modulated waveform. The minor modulation waveform of both curves is saw-tooth. Both curves repeat indefinitely.

It can be seen from FIGS. 4 and 7 and the above description that this invention needs no simultaneous modulated drive roll speed to coincide with the modulated traversal rate. Also, it can be seen that it is unique with this invention to modulate the set point of the traverse rate as opposed to presetting it or presetting then decreasing it, while continuously superimposing the minor modulation along or within the modulated set point. the prior art requires complex timing mechanisms and/or coordination of winding speed with traverse rate. Also, with initial pre-set method, each winder would require an inverter. The method of this invention permits driving many traverse motors from one inverter, and does not require the waveform to be timed with package size as the package builds.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic showing a typical surface driven winder connected to inverters for the print roll and traverse motors.

FIG. 2 shows a preferred embodiment for modulating the set point for the electrical input to the traverse motor.

FIG. 3 shows the prior art, unmodified speed adjust.

FIG. 4 is an example of the waveform of this invention.

FIG. 5 is an example of the prior art waveform.

FIG. 6 is a bar graph showing the number of ribbons formed winding a package using a waveform of this invention.

FIG. 7 shows a wave form used to feed the traverse motor during the time the data was gathered for FIG. 6.

FIG. 8 is a bar graph showing the number of ribbons formed in the control experiment using the prior art waveform shown in FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, yarn 1 is traverse wound through traverse device 2 powered by traverse motor 3 and transferred by print roll 4 onto package 5. Electrical input to traverse motor 3 comes from traverse inverter 7 through line 9. Electrical input to the print roll motor behind or within print roll 4 comes from print roll inverter 6 through line 8. The schematic equipment shown within box 10 represents a typical surface driven winder. The inverters have speed adjust knobs l1 and 12.

Referring to FIG. 2, a method of modulating the set point is shown imposed into the circuit of speed adjust potentiometer 17 which is connected to inverter circuit 13. A 360 rotating potentiometer 114 is connected with electrical lines 18 and 19 into the circuit. A small motor 15 such as a clock motor rotates the potentiometer 14. Motor 15 is driven by l 10 volts electrical source 16. This embodiment would be adjusted by speed adjust knob 12.

Prior art is shown in FIG. 3 wherein inverter circuit I3 simply has speed adjust potentiometer 17 which can be adjusted such as by speed adjust knob 11.

Referring to FIG. 4, the waveform of this invention is demonstrated showing the output: frequency which is the electrical input for traverse motor along the vertical scale and time along the horizontal scale. The amplitude of the minor modulation is shown to be the distance between the tips of the arrows labeled 20. The amplitude of the major modulation is shown to be the distance between the tips of the arrows labeled 21.

FIG. 5 shows a typical prior art waveform having a pre-set point showing a straight line about which the amplitude of modulation varies by a minor amount.

FIGS. 6 to 9 are bar graphs and waveforms which are explained in the following example.

EXAMPLE Textured 2,600 denier yarn was wound at 4,500 feet per minute using the prior art waveform for traverse rate as compared to the waveform of this invention. The same yarn was used for both the prior art control package and the package using the waveform for traverse rate of this invention. The yarn had standard finish, 36 entanglements per meter, 12 crimps per inch and was wound onto package having a final diameter of 9- inches and weighing 11 pounds. The winding time was 15.5 minutes. The waveform when the package was wound according to this invention is shown in FIG. 7. The results in the number of ribbons formed per 30 second (one-half minute) interval are shown in FIG. 6. The prior art waveform for the control wound package is shown in FIG. 9. The results of the number of ribbons per 30 second interval are shown in FIG. 8. Comparison of the two bar graphs makes it clear that ribbons are successfully reduced to an amount which is acceptable for processing requirements. The package formed was commercially acceptable in other parameters in that it was flat-ended and had no other serious flaws described in the Background of the Invention.

When using the traverse rate waveform of this invention, the minor amplitude should be 1 to 6 percent, preferably 2 percent. The period of the minor waveform should be 0.5 to 5.0 seconds, preferably about 2 to 3 seconds. The amplitude of the major waveform should be 2 to 12 percent, preferably about 8. The period of the major waveform should be 0.25 to 2.0 minutes, preferably about 0.5 to 1.0 minute. The amplitude of the minor waveform should not be greater than 50 percent of the major amplitude. In addition to the method of using a clock motor Orother constant rpm motor to drive a 360 rotating potentiometer shown in FIG. 2, the major modulated waveform can be generated using solid state electronics such as with capacitors. Also for just one winder in special circumstances, the potentiometer could be rotated by hand.

Iclaim:

1. In a method of winding a cylindrical substantially flat-ended yarn package on a surface driven winder in layers of helical coils of yarn by forwarding yarn at a substantially constant speed, rotating the package at a substantially constant peripheral speed, and traversing the yarn back and forth across the package at a varying speed by a cam drive with a traverse motor with an inverter having the electrical output frequency modulated from a predetermined rate, the improvement comprising varying said speed of said traverse by constantly varying said predetermined rate of the inverter electrical output in a non-linear major modulated waveform while constantly maintaining said frequency modulation from said predetermined rate, resulting in a plot of frequency of said inverter electrical output versus time which can be described as a minor modulated waveform continuously superimposed within a major modulated waveform, said minor modulated waveform having an amplitude of about I to 6 percent of the predetermined rate, said major modulated waveform having an amplitude of about 2 to 12 percent of the predetermined rate, said minor modulated waveform having a period of about 0.5 to 5 seconds, said major modulated waveform having a period of about 0.25 to 2.0 minutes, and the amplitude of the minor modulated waveform being less than one-half the amplitude of the major modulated waveform, so that ribbons are prevented in said package, and so that no simultaneous modulated drive roll speed to coincide with the modulated traversal rate is needed.

2. The method of claim 1 wherein said non-linear major modulated predetermined rate takes the form of a sinusoidal curve.

3. The method of claim 2 wherein said minor waveform has an amplitude of about 2 percent of the predetermined rate, said major waveform has an amplitude of about 8 percent of the predetermined rate, said minor waveform has a period of about 2 to 3 seconds, and said major waveform has a period of about 0.5 to

1 minute. 

1. In a method of winding a cylindrical substantially flat-ended yarn package on a surface driven winder in layers of helical coils of yarn by forwarding yarn at a substantially constant speed, rotating the package at a substantially constant peripheral speed, and traversing the yarn back and forth across the package at a varying speed by a cam drive with a traverse motor with an inverter having the electrical output frequency modulated from a predetermined rate, the improvement comprising varying said speed of said traverse by constantly varying said predetermined rate of the inverter electrical output in a nonlinear major modulated waveform while constantly maintaining said frequency modulation from said predetermined rate, resulting in a plot of frequency of said inverter electrical output versus time which can be described as a minor modulated waveform continuously superimposed within a major modulated waveform, said minor modulated waveform having an amplitude of about 1 to 6 percent of the predetermined rate, said major modulated waveform having an amplitude of about 2 to 12 percent of the predetermined rate, said minor modulated waveform having a period of about 0.5 to 5 seconds, said major modulated waveform having a period of about 0.25 to 2.0 minutes, and the amplitude of the minor modulated waveform being less than onehalf the amplitude of the major modulated waveform, so that ribbons are prevented in said package, and so that no simultaneous modulated drive roll speed to coincide with the modulated traversal rate is needed.
 2. The method of claim 1 wherein said non-linear major modulated predetermined rate takes the form of a sinusoidal curve.
 3. The method of claim 2 wherein said minor waveform has an amplitude of about 2 percent of the predetermined rate, said major waveform has an amplitude of about 8 percent of the predetermined rate, said minor waveform has a period of about 2 to 3 seconds, and said major waveform has a period of about 0.5 to 1 minute. 